全文获取类型
收费全文 | 22891篇 |
免费 | 482篇 |
专业分类
财政金融 | 4038篇 |
工业经济 | 1618篇 |
计划管理 | 3939篇 |
经济学 | 5412篇 |
综合类 | 244篇 |
运输经济 | 176篇 |
旅游经济 | 341篇 |
贸易经济 | 3783篇 |
农业经济 | 1145篇 |
经济概况 | 2600篇 |
信息产业经济 | 3篇 |
邮电经济 | 74篇 |
出版年
2023年 | 111篇 |
2021年 | 150篇 |
2020年 | 285篇 |
2019年 | 455篇 |
2018年 | 499篇 |
2017年 | 526篇 |
2016年 | 515篇 |
2015年 | 351篇 |
2014年 | 566篇 |
2013年 | 2412篇 |
2012年 | 784篇 |
2011年 | 812篇 |
2010年 | 706篇 |
2009年 | 798篇 |
2008年 | 733篇 |
2007年 | 642篇 |
2006年 | 609篇 |
2005年 | 531篇 |
2004年 | 464篇 |
2003年 | 474篇 |
2002年 | 424篇 |
2001年 | 506篇 |
2000年 | 459篇 |
1999年 | 416篇 |
1998年 | 472篇 |
1997年 | 423篇 |
1996年 | 421篇 |
1995年 | 359篇 |
1994年 | 369篇 |
1993年 | 354篇 |
1992年 | 363篇 |
1991年 | 379篇 |
1990年 | 345篇 |
1989年 | 254篇 |
1988年 | 263篇 |
1987年 | 267篇 |
1986年 | 248篇 |
1985年 | 358篇 |
1984年 | 354篇 |
1983年 | 331篇 |
1982年 | 284篇 |
1981年 | 285篇 |
1980年 | 284篇 |
1979年 | 278篇 |
1978年 | 226篇 |
1977年 | 183篇 |
1976年 | 182篇 |
1975年 | 162篇 |
1974年 | 149篇 |
1973年 | 148篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
901.
Maas Cora J. M. Hox Joop J. Lensvelt-Mulders Gerty J. L. M. 《Quality and Quantity》2004,38(4):381-389
The goal of meta-analysis is to integrate the research results of a number of studies on a specific topic. Characteristic for meta-analysis is that in general only the summary statistics of the studies are used and not the original data. When the published research results to be integrated are longitudinal, multilevel analysis can be used for the meta-analysis. We will demonstrate this with an example of longitudinal data on the mental development of infants. We distinguish four levels in the data. The highest level (4) is the publication, in which the results of one or more studies are published. The third level consists of the separate studies. At this level we have knowledge about the degree of prematurity of the group of infants in the specific study. The second level are the repeated measures. We have data about the test age, the mental development, the corresponding standard deviations, and the sample sizes. The lowest level is needed for the specification of the meta-analysis model. Both the way in which the multilevel model has to be specified (the Mln-program is used) as the results will be presented and interpreted. 相似文献
902.
Performance of empirical Bayes estimators of random coefficients in multilevel analysis: Some results for the random intercept-only model 总被引:1,自引:0,他引:1
Math J. J. M. Candel 《Statistica Neerlandica》2004,58(2):197-219
For a multilevel model with two levels and only a random intercept, the quality of different estimators of the random intercept is examined. Analytical results are given for the marginal model interpretation where negative estimates of the variance components are allowed for. Except for four or five level-2 units, the Empirical Bayes Estimator (EBE) has a lower average Bayes risk than the Ordinary Least Squares Estimator (OLSE). The EBEs based on restricted maximum likelihood (REML) estimators of the variance components have a lower Bayes risk than the EBEs based on maximum likelihood (ML) estimators. For the hierarchical model interpretation, where estimates of the variance components are restricted being positive, Monte Carlo simulations were done. In this case the EBE has a lower average Bayes risk than the OLSE, also for four or five level-2 units. For large numbers of level-1 (30) or level-2 units (100), the performances of REML-based and ML-based EBEs are comparable. For small numbers of level-1 (10) and level-2 units (25), the REML-based EBEs have a lower Bayes risk than ML-based EBEs only for high intraclass correlations (0.5). 相似文献
903.
S.M. Amadae 《American journal of economics and sociology》2004,63(1):161-165
ABSTRACT . “Bargaining with the Devil: Commentary on the Ostroms’‘Quest for Meaning in Public Choice’” provides a commentary on Elinor Ostrom and Vincent Ostrom's paper, “The Quest for Meaning in Public Choice.” This discussion focuses on the challenging tension that exists between social scientific knowledge and social practices. It suggests that historical agents may have solved the dilemma of cooperation prior to rational choice theorists’ invention of the public goods problem. 相似文献
904.
Robustness issues in multilevel regression analysis 总被引:8,自引:0,他引:8
A multilevel problem concerns a population with a hierarchical structure. A sample from such a population can be described as a multistage sample. First, a sample of higher level units is drawn (e.g. schools or organizations), and next a sample of the sub‐units from the available units (e.g. pupils in schools or employees in organizations). In such samples, the individual observations are in general not completely independent. Multilevel analysis software accounts for this dependence and in recent years these programs have been widely accepted. Two problems that occur in the practice of multilevel modeling will be discussed. The first problem is the choice of the sample sizes at the different levels. What are sufficient sample sizes for accurate estimation? The second problem is the normality assumption of the level‐2 error distribution. When one wants to conduct tests of significance, the errors need to be normally distributed. What happens when this is not the case? In this paper, simulation studies are used to answer both questions. With respect to the first question, the results show that a small sample size at level two (meaning a sample of 50 or less) leads to biased estimates of the second‐level standard errors. The answer to the second question is that only the standard errors for the random effects at the second level are highly inaccurate if the distributional assumptions concerning the level‐2 errors are not fulfilled. Robust standard errors turn out to be more reliable than the asymptotic standard errors based on maximum likelihood. 相似文献
905.
The Boston mechanism is a popular student-placement mechanism in school-choice programs around the world. We provide two characterizations of the Boston mechanism. We introduce two new axioms; favoring higher ranks and rank-respecting invariance. A mechanism is the Boston mechanism for some priority if and only if it favors higher ranks and satisfies consistency, resource monotonicity, and rank-respecting invariance. In environments where each type of object has exactly one unit, as in house allocation, a characterization is given by favoring higher ranks, individual rationality, population monotonicity, and rank-respecting invariance. 相似文献
906.
Israel M. Kirzner 《The Review of Austrian Economics》2014,27(2):119-128
This article explores certain aspects of James Buchanan’s struggles, over a period of years, to come to grips with Austrian subjectivism in economic theory. 相似文献
907.
Torben M. Andersen 《Journal of Economics》2014,111(1):1-27
Trend increases in longevity are a global phenomenon challenging the fiscal sustainability of current welfare arrangements. Policy proposals abound and often build on implicit assertions concerning intergenerational equity. This paper offers a simple but manageable OLG model with endogenous retirement and cohort-specific longevity to address intergenerational redistribution and risk sharing. While it is well known that a utilitarian planner strives for consumption smoothing, it is shown that healthy ageing calls for work smoothing in the sense that retirement ages increase with longevity. Hence, cohorts with higher longevity should contribute to their larger consumption needs via later retirement, although it is shown that the planner still front-loads some financing (pre-saving). Stochastic longevity raises the issue of intergenerational risk sharing, which implies that cohorts turning out to have a high longevity are compensated at the expense of cohorts turning out to have a relatively short longevity. 相似文献
908.
Goode CJ Tanaka DJ Krugman M O'Connor PA Bailey C Deutchman M Stolpman NM 《Nursing economic$》2000,18(4):202-207
The aim of evidence-based guidelines is primarily to improve patient outcomes without adding to the existing cost of care because both payers and policymakers want to identify health care costs that do not result in benefit to the patient. The purpose of the reported project was to generate a practice guideline for the treatment of uncomplicated acute cystitis in a female population, to determine the extent to which the guideline would be used by providers and to measure the cost and quality of outcomes from its use. A retrospective chart review was used to gather pre-guideline practice and cost data. Measurements included the type, frequency, and duration of antibiotic therapy and the use of urine cultures and both complications and routine followup visits. The implementation of an outpatient practice guideline resulted in a significant change in antibiotic prescribing and a trend toward a change in ordering cultures and clinic followup. There was also a significant decrease in treatment costs. 相似文献
909.
In this paper the authors introduce a novel approach to stochastic image processing, denoted as Differential Markov Random Field (DMRF), which has been applied to gravity anomaly separation problems. The advantages of the method are that it introduces only little distortion into the shape of the original image and that it is not affected significantly by factors such as the overlap power spectra of regional and residual fields. Testing of the proposed meth using synthetic examples gave excellent results. 相似文献
910.